FILICES. 459 



olate ; segments oblong, obtuse, crenate-serrate, decurrent, the lower ones 

 nearly distinct ; son nearly marginal, distinct. Nephrodium marginale 

 Mich. 



Rocky woods. Can. to Car. July. 1\.. Fern 12 18 inches high. Stipe 

 stout, chaffy, especially near the root, with large tawny scales. Frond ovate- 

 oblong, smooth, bluish-green, the upper part only fertile. Sori middle-sized, 

 one at each notch in the segments. Indusium peltate-reniform. 



Marginal Shield-fern. 



7. A. dilatatum Swartz : stipe chaffy ; frond bipinnate ; the pinnules 

 oblong, distinct, deeply and incisely pinnatifid ; segments mucronate-ser- 

 rate; sori minute, distinct, in a double row about the middle of the pinnules. 

 A. intermedium MM. A. spinulosum Pursh. Nephrodium cristatum Mich. 



Shady woods. Can. to Virg. July. 1\. Stipe 612 inches long, pale 

 brown, chaffy with thin brown scales. Frond 1218 inches long, ovate-Ian 

 ceolate in its outline, varying in the divisions of the pinnce, sometimes almos* 

 tripinnate ; serratures of the segments cuspidate or sharply acuminate. Son 

 rather small, numerous, somewhat in two rows, brownish. Indusium umbilicatt! 

 in the centre. Dilated Shield-fern. 



8. A. aculeatum Swartz: stipe and rachis chaffy; frond bipinnate; 

 pinnules ovate, somewhat falcate, slightly petioled, mucronate-serrate, ob- 

 liquely truncate and auricled at the base on the upper side, obtusely cuneate 

 on the lower, upper ones fructiferous. ( Torr. N. Y. FU.} 



White mountains, N. H. Green Mountains, Vt. Mountains of Essex county, 

 N. Y. Aug. 7J.. Stipe 2 6 inches long, and with the rachis clothed with 

 chaffy lanceolate-subulate scales. Frond 1% 2 feet long, of a rigid texture, 

 broad-lanceolate in its outline. Sori rather large, 6 8 on each pinnule, near 

 the middle. Indusium reniform-peltate. Prickly Shield-fern. 



4. WOODSIA. Brown. Woodsia. 

 (Named in honor of Joseph Woods ; an English botanist.) 

 Sori globose. Indusium more or less globose or cup-shaped, 

 seated under the sorus, and at length cut at the margin into 

 numerous often capillary segments. Spore-cases globose, pedi- 

 cellate. 



1. W. ttvensis Brown : frond lanceolate, pinnate ; pinnae oblong, obtuse, 

 deeply pinnatifid ; segments oblong, obscurely crenate, the under surface as 

 well as the rachis and stipe chaffy. W. Ilvensis and rufidula Deck Bot. 

 1st. Ed. Polypodium Ilvense Swartz. 



Rocky banks of streams, Subarct. Amer. to Car. June. 7J.. Fern 4 6 

 inches high, growing in dense tufts. Fronds 2 4 inches long, the under surface 

 clothed with rusty scales; pinnce about 12, alternate. Sori small, near the 

 margin of the segments, at length confluent. Indusium surrounding the slightly 

 pedicellate spore-cases, the margin cut into numerous capillary segments. 



Oblong-leaved Woodsia. 



2. W. hyperborea Brown, : frond lanceolate, pinnate ; pinnae ovate-cordate, 

 incisely pinnatifid, covered with chaffy hair beneath ; segments rounded, 

 unequal. Polypodium hyperboreum Swartz. 



In clefts of rocks. Can. and on the higfc mountains of Perm, and Virg 

 Pursh. July. 7|. Resembles the preceding, but is sometimes quite small, and 

 differs in having the pinnae as well as the segments more rounded and less deeply 



